Babak Fallahazad, Yufeng Hao, Kayoung Lee, Seyoung Kim, R. S. Ruoff, E. Tutuc
We examine the quantum Hall effect in bilayer graphene grown on Cu substrates
by chemical vapor deposition. Spatially resolved Raman spectroscopy suggest a
mixture of Bernal (A-B) stacked and rotationally faulted (twisted) domains.
Magnetotransport measurements performed on bilayer domains with a wide 2D band
reveal quantum Hall states (QHSs) at filling factors $\nu=4, 8, 12$ consistent
with a Bernal stacked bilayer, while magnetotransport measurements in bilayer
domains defined by a narrow 2D band show a superposition of QHSs of two
independent monolayers. The analysis of the Shubnikov-de Haas oscillations
measured in twisted graphene bilayers provides the carrier density in each
layer as a function of the gate bias and the inter-layer capacitance.
View original:
http://arxiv.org/abs/1202.2930
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